Power steering mechanism



Sept. 25, 194-5. H. BAADE 2,385,485

' POWER STEERING MECHANISM Filed Sept. 2, 1943 5 Sheets-Sheet 1 JNVENTOE HENRY BAADE Sept. 25, 1945. BAADE POWER STEERING MECHANISM Filed Sept. 2, 1943 5 Sheets-Sheet 2 IN VENTOR HEN/P Y 5A A DE Sept. 25, BAADE POWER STEERING MECHANISM Filed Sept. 2, 1943 5 Sheets-Sheet 3 .l 8 5 0 4 5 L\ 4 6 m. 4 M M F 4 8 2 6 M; a a

I, HENRY BAADE BY Sept. 25, 1945. HI A h POWER STEERING MECHANISM Filed Sept. 2 1943 5 Sheets-Sheet 4 h mw JNVENTOR HEN/P) BAADE Ru N k3 w I I Q L w km 3 mm Sept. 25, 1945. H. BAADE POWER STEERING MECHANISM Filed Sept. 2, 1943 5 Sheets-Sheet 5 R WM m A W. A B w m H Y B Q & & .wm QW v? w Nx Patented Sept. 25, 1945 POWER STEERING MECHANISM Henry Baade, South Bend, Ind., assignor to Bendix Aviation Corporation, South Bend, 11111., a corporation of Delaware Application September 2, 1943, Serial No. 500,881

8 Claims.

This invention relates to steering mechanism and more particularly to power-operated steering mechanisms adapted for use in connection with vehicles having dirigible wheels.

One of the objects of the present invention is to provide a novel power-operated steering mechanism which is especially adapted for use in connection with motor vehicles.

Another object of the invention is to provide movable parts of a follow-up control valve of said steering mechanism. It is an object of my invention to so construct and arrange the parts of this force transmitting means that the aforementioned follow-up and feel functions of the mechanism are readily effected in the operation of controlling the power steering mechanism constituting my invention.

The above and other novel features of them-- in a motor vehicle steering apparatus a novel vention will appear more fully hereinafter from construction whereby the operator may readily the following detailed description when taken in steer motor vehicles of the larger type, such as connection with the accompanying drawings, trucks or busses, with a minimum amount of wherein one embodiment of the invention is ileffort and at the same time have complete conlustrated. It is to be expressly understood, howtrol of the steering of such vehicles as heretofore. 1 ever, that the drawings are for purposes of il- Still another object is to provide a novel power lustration only and are not designed as a definisteering mechanism for motor vehicles so constition of the limits of the invention, reference betuted as to enable manual control of the steering had for this purp to the ppended claims. ing ope-ration to effect a combined manual and In the drawings, wherein similar reference power steering operation. characters denote similar parts throughout the A further object is to provide in a mechanism several views: of the above character, a novel arrangement of Figure 1 is a side elevational view of a portion parts whereby manually controlled power operaof an automotive Vehicle disclosing e Po tion of the steering apparatus will include a feel steering mechanism constituting my invention; or reaction which will be reflected in the manu- Figure 2 s a P an View f a p on o an ut ally controlled member in order to simulate'as motive vehicle disclosing the power steering closely as possible the feel or resistance heretomechanism of myinvelltioll; fore encountered during manual steering. i Figure 3 d s s s n a nt f a p rt n Another object of the invention is to provide 0f the power steering c a disclosed in a pressure differential operated power steering e said po ti including the D ma ar one mechanism for motor vehicles controlled by a [of he idler levers and parts connected thereto; novel follow-up valve mechanism having two rel- Figure 4 is an end view of the D an arm a atively movable valve elements one of said elep rts connected thereto, all as disclosed in Fi ments being connected, through the intermediary 1117B of a lever, to the steering wheel of the vehicle i r 5 is n n ew f t d r lever a d and to the aforementioned means for obtaining D t nected thereto, all as disclosed in Fi the feel or reaction of the mechanism and the e other of said elements being. connected to the Fi 6 is a longitudinal Sectional e ta power element of the motor of said mechanism. n t line of Figure 2 disclosing t p s- A still further object is to provide in a powersure differential operated motor and control valve operated steering mechanism for motor vehicles, of my invention; a novel, simple and compact arrangement of Figure 7 is a view, partly in Section and p t y parts so constituted as to be relatively light in in plan, taken n e l ne '|l of Figure 6; weight and capable of ready installatio with- Figure 8 is a sectional view, taken on the line out the necessity of completely rebuilding manu- 88 of F r ,dis o in a p r f th v v nally-operated steering mechanisms now in comeratinglinkage; and mon use. Figure 9 is an enlarged sectional view, similar The most important object of my invention to Figure 6, disclosing details of the pressure difhowever is to p vid i a power steering mechferential operated motor and follow up control anism, a very simple and compact force trans- Valve of my e mitting means, including relatively movable jux- Referring to the dra the mechanism (115- taposed members extending parallel to and adclosed therein constituting a p r d embodijacent the frame of the vehicle, interconnecting m nt f y invention includes a m lly pthe vehicle steering wheel, the drag link of a conerable steering shaft l0 Operated y a Steering ventional steering mechanism and the relatively wheel l2. This shaft, which is housed within a steering post I4, is operable connected by any suitable means, such as a worm and sector unit I6, to a rotatable shaft IS. The shaft I extends through and is detachably secured to the end portion 20 of a pitman arm 22. A pin 24, fixedly secured to and extending through the lower end of said pitman arm, serves as a mounting for one end of a strap member 25 which member is preferably provided with an enlarged central portion 28 having an opening 29 therein, circular in outline. Through this opening there extends a reduced portion 30 of a pin 32 extending laterally from the lower end of an idler lever 34. This lever, as disclosed in Figure 5, is preferably fixedly mounted upon the outer end of a pin 38 which extends through and is preferably detachably secured by a nut 40 to a bearing member 42 secured to the frame member 44 of the vehicle.

One end of the strap member 20 is bent laterally outwardly to provide a portion 46 to which is detachably secured a pin 08. This pin 48, which is secured to the portion 06 by nuts50 and 52, is provided with an enlarged end portion 50 press fitted within one end of a tube 56. This tube, as disclosed in Figures 2, 6 and 7, is housed within a tube 58 and is bifurcated at its end to receive one end of a tubular shaped pin 60 which is pivotally connected to the tube 56 by a pin 62. As disclosed in Figure 8, the end of the pin 60 is shaped to provide an annular groove 66 which groove receives a pin 68. The ends of the pin 68 are mounted within openings in a valve operating lever 10 and this lever, which is preferably u-shaped at its upper end is positioned between the relatively thick side walls 12 and 10 of a cup-like end member I1 of a control unit 16. As disclosed in Figure 8 a pin 13 extends through the end of the lever 10 and through one end of a valve operating pin I; and the valve operating 1 means also includes a pin I8, said pin bein mounted in the side walls I2 and and extendin through the Ushaped end of member 10.

Describing now the parts of control valve unit 16, one end of a parallelopipedon 80 is telescoped Within the edge portion of the aforementioned member 11 and secured thereto b fastenings B2, The parallelopipedon is provided with slots 80 and 86, Figures 7 and 9, extending therethrough and said member is bored to receive a tubular shaped sleeve member 88 fixedly mounted in the parallelopipedon and having openings 90. 92, 90 and 96 therein; and said member is also bored to receive one end of a tube 98 which is press fitted at 99 over the end of the pin 60 said tube being fixedly secured at its other end to a flexible diaphragm I00 housed within the power element I 0I of a pressure differential operated motor I02, As disclosed in Figure 9 rectangular shaped plates I00 and I06, secured to the member 80 by fastenings I08 and I09 respectively, serve to cover the outer ends of said slots thereby providing two pockets within the valve unit. When the parts of the follow up valve 16 are in the position disclosed in Figure 9, that is when said valve is in its closed position to render the power steering mechanism of my invention inoperative, a recess 9| of a spool shaped valve member 93 registers with the ports 90, 92, 90, 96 there- I03, a port I05 in by connecting compartments 95 and 91 of the motor I02 with the intake manifold 99 of the internal con'ibustion engine I60 of the vehicle; accordingly the power mechanism of my invention llli'lllClffS what is known in the art as a vacuum suspended motor. Springs 95 and 91 may be housed within the motor I02 to bias the ports of tively the valve to this position: for as will be apparent from an inspection of Figure 9 the valve parts 93 and 88 areoperably connected to the diaphragm member I00 and the member I22 respecand the relative position of said members is determined by the springs 95 and 91 Tracing the then existing air transmitting connections between the intake manifold and compartments 95 and 91 the recess 9| is connected with the manifold by an air transmitting conduit the plate I06 and registering ports I07 and I01 in the parallelopipedon and sleeve 88 respectively; and the recess 9I in the valve member 93 is connected with the compartment 95-via the ports 90 and 94,slot 84 in the parallelopipedon 80, a port III in the tube 98, the interior of said tube, a compartment II3 outlined by the diaphragm I00 and the plate I20 and interconnected Openings in the members I00, H0, H6, H8, I20 and I22 providing a duct H1. The recess BI is connected with the compartment 91 via ports 92 and 96 in the sleeve 88, the slot 86, the interior of the tube I26, a compartment H5 outlined by the diaphragm I00 and the plate I22 and a duct I I9 provided by openings in the aforementioned members I00, H4, H6, H8, I20, and I22.

The motor I02 constitutes no part of my invention for as stated above my invention is limited to the construction and arrangement of the parts of the follow up Valve disclosed in Figure 9 and the construction and arrangement of the parts of the force transmitting means interconnecting said valve, the steering wheel and the drag link of the steering mechanism.

Briefly describing the motor I02 the same comprises a casing I04 which. as disclosed in Figure 2, may be pivotally connected by means of bracket members I06, I06 I09 and H0 to a support II2 extending laterally from the frame member 90. As disclosed in Figure 9 the power element IOI of the motor I02 preferably comprises rings H0 and H6 angular shaped in cross section, said rings being placed back to back and clamping therebetween two seals H8 and I20 also angular shaped in cross section. Between the latter members there is positioned the flexible diaphragm I00 which is sleeved over and fixedly secured at I2I to the end of the tube 98. The members I00, H0, H6, H8, and I20 are clamped together at their peripheries by plates I22 and I20 suitable fastenings I26 securing the parts together. Plate I22 is fixedly secured at its center to a tubular rod I26 which houses the rod 98 and acting together the plates I22 and I20 constitute the power element of the motor I02. The rod I26 extends through an end plate I28 of the motor I02 and is threaded]; connected at its other end with a portion of the parallelopipedon and as disclosed in Figure 6 an expansible and contractable cover member I30 is connected at one of its ends to the end plate I28 and at its other end to a plate I32 mounted on one end of the valve unit 16. The plate I32 is provided with an opening 16 therein, Figures 6 and 9, said opening. together with the aforementioned air transmitting connections with the air cleaner I23, providing means for supplying sufiicient air to the interior of the valve housing.

Completing the description of the force transmitting means interconnecting the power element IOI and the drag link I32 of the conventioned steering mechanism, said means includes furca-' ber 44 These furcations straddle the pin 60 and abut spaced apart ears I38 and I40 extending from the body of the member 11; and through said fur-cations and ears there extends a pin I42 said pin also extending through spaced apart ears or furcations I44 and I46 extending from the end of the tube 58 and fixedly secured there- It is to be noted, as disclosed in Figures 7 and 9, that the pin I42 extends through an opening I48 in the pin 60 which opening is of a diameter such as to make possible a movement of the pin 60 to open the valve, all as will be described hereinafter. without however moving said pin 60 and the parts connected thereto.

As disclosed in Figure 3 the end of the tube 58 is fixedly connected, as by spot welds, to an end portion I50 of a bar I52 said end portion extending at right angles to the body of said bar. As

disclosed in Figure the bar I52 is supported by the pin 32 which extends laterally from the movable idler lever 34 and, as disclosed in Figure 4, the end of said bar is provided with an opening I54 through which extends the pin 24 the diameter of said opening being such as to make possible a movement of the strap 25 to crack, that is open, the Valve 16 before the bar I52 and the parts connected thereto are moved. As disclosed in Figure 2 the drag link I32 is connected to the bar I52 by a pin I54 extending through said bar and connected thereto by a nut I56; and a ball on the end of the pin I54 fits within a socket in the end of the drag link to provide a conventional ball and socket joint I58.

As disclosed in Figure 2 the drag link I32 constitutes a part of a conventional steering mechanism of an automotive vehicle, said vehicle, as

shown in Figures 1 and 2, including steering wheels I60 and I62 and an internal combustion engine I64; and said steering mechanism includes the usual steering arms I66, a tie rod I68 and a curved steering lever I connected to the drag link.

Describing now the operation of the power steering mechanism constituting my invention and incidentally completing the description of the parts thereof when it is desired to turn the front wheels I60 and I62 to effect a right turn of the vehicle the steering wheel I2 is, of course, turned to the right. As will appear from an inspection of Figures 1 and 3 this operation results in a counterclockwise movement of the pitman arm 22 which in turn results in a movement to the right, Figure 9, of the valve member 93 which is pivotally connected to the valve operating lever 10 by adjustably connected links I13 and I14; for when the pitman arm 22 i rotated counterclockwise the strap 25, by virtue of its lost motion connection with the lever 34 and bar I52, is moved to the right thereby moving the tube 56 which is, through the intermediary of the pin 60, connected to the valve operating lever 10.

In this valve cracking operation the lever 10, operating as a lever of the third class, fulcrums on the pin 18; for when the steering Wheel is rotated to the right to crack, that is open the valve, the resistance to movement of the parallelopipedon 80, which is connected to the ,drag link, is great enough to prevent a movement of said member 80 and the pin 18 mounted on the side walls of the end member 11 which is secured to that is the movement to the right of the valve.

member 93, results in a venting of the compartment-95 to the atmosphere; for when said valve member is so moved the air flows into the compartment 95 via an air cleaner I23, Figure 1, a conduit I25. a port I21 in the end plate I28 of the motor I 02, the interior of the expansible cover member I30, the interior. of the valve member 93, the ports 90 and 94 which are then uncovered. the slot 84, the port III, the interior of the tube 98, the compartment H3 in the motor I02, and the duct H1. The compartment 91 of the motor I02 however remains connected, at this time, with the source of vacuum, that is the intak manifold 99; for when the valve member 93 is moved to the right to effect a right turn operation of the power steering mechanism the ports 92 and 96 remain in registry with the recess 9| which is connected to said manifold.

The compartments 95 and 91 being connected respectively with the atmosphere and a source of vacuum, the piston IN is then subjected to a differential of pressures resulting in its movement to the right, Figure 9; and this operation, by virtue of the above described connection between the piston IOI and drag link I02; results in a movement of said drag link to the right to effect a right turn steering operation of the vehicle.

It is to be noted at this juncture that at the same time the motor I02 is energized to effect this right turn operation of the steering wheels the driver is conscious of the operation of the motor by virtue of a resistance to movement of the steering wheel to maintain the valve 16 open. This resistance to movement or so-called feel results from the differential of pressures to whichthe diaphragm I00 is at the time subjected, said differential of pressures being the same as that to which the piston IN is subjected; for it is noted from an inspection of Figure 9 that when the motor I02 is energized to move the power element IM to the right the compartment I I3.of said mo tor is at the time vented to the atmosphere and the compartment II5 of said motor is connected to the manifold. The diaphragm I00 is accordingly subjected to a differential of pressures tending to move the same to the left, Figure 9, and this differential of pressure provides the desired resistance to movement of the steering wheel.

Describing now the follow up operation of the control valve 16 if the driver should, during the above described operation of the steering mechanism, stop, that is arrest the turning movement of the steering wheel I2 after said valve is open, then the movement of the pin 60 and all parts connected thereto includin the pin 66 will of course also be stopped. It is to be remembered however, that at this time the motor I02 is energized and the piston IOI is accordingly in motion. It follows therefore that said piston will continue its movement to the right, Figure 9, until the parallelopipedon 80, which together with the sleeve 08 constitutes one of the two parts of the follow up valve and which is connected to said piston, moves to the right far enough to lap the valve.

Now describing this lapping operation of the valve'the member moves to the right. Figure 9, until the ports and 94 in the sleeve 86 are covered by land portions of the valve member 93; and when this happens the flow of air into the compartment 95 is stopped. The movement of the piston IOI then stops inasmuch as the forces acting upon the same are in equilibrium. It is also to be noted here that as the member 80 moves to the right in this follow up to lap 0Derthe left thereby completing this operation of the valve in a very short period of time; for when the pin 68 is held stationary, that is when the movement of steerin wheel is arrested, and when the member 80 is moved to the right, then the lever 70 functions as a lever of the first class the pin 68 becoming the fulcrum. The resulting clockwise movement of the lever 10 effects the aforementioned leftward movement of the valve member 93 to expedite the lapping operation of the valve, that is expedite the registering of the ports 90 and 94 with the land ports HI and I33 respectively.

If now the driver desires to effect another increment of turningmovement of the wheels I60 and IE2, he again turns the steering wheel to the right whereupon the valve 16 is again opened, and this results in the motor I02 being again energized to continue the turning movement of the wheels.

If a left turn operation of the steering wheels is desired the driver will of course turn the steering wheel to the left; and this operation, as will be apparent from the description of the mechanism given above, results in a movement of the valve member 93 to the left, Figure 9, with a resulting power movement of the piston IOI to the left; and this movement of the piston effects a movement of the drag link resulting in a left turn movement of the steering wheels.

There is thus provided a simple and effective power steering mechanism for operat'ng the conventional steering mechanism of an automotive vehicle; for but a limited effort is required to open the valve 16 to thereby initiate an operation of the motor I02 and the driver is, by virtue of the so-called feel, at all times conscious of the force being exerted by power element, that is piston lfll of said motor. If the force exerted by the piston is insufficient to effect the desired steering operation the driver. by taking up the lost motion between thepin 24 and bar I52, Figure 4, or between the portion 28 of the strap 25 and the member 30, Figure 5, or between the pin 60 at the pin I42. Figure 9, whichever is the lesser, may add his physical effort to the force exerted by the motor I02; and, by virtue of the above described follow up action of the valve 16, the driver may effect the turning of the steering wheels in a plurality of increments of movement of the steering wheel.

I claim:

1. In a power steering mechanism for the dirigible wheels of a motor vehicle comprising a frame member extending parallel or substantially parallel to the ground, a pitman arm adapted to be manually oscillated in opposite directions for steering. a drag link, a double ended double acting pressure differential operated motor, a twopart follow up valve for controlling the operation of said motor and mounted adjacent thereto, both parts of said valve being moved to effect said controlling operation. and force transmitting means interconnecting the power element of the motor, the pitman arm, the two parts of the control valve and the drag link, said force transmitting means consisting of a plurality of juxtaposed relatively movable elements extending parallel or substantially parallel to said frame member and further consisting of a lever member connected to both of said valve parts, said member fulcruming at one point when the valve is opened and fulcruming at another point when the valve is lapped.

2. In a power steering mechanism for the dirigible wheels of a motor vehicle comprising a frame member extending parallel or substantially parallel to the ground, a pitman arm mounted on said frame member and adapted to be manually oscillated in opposite directions for steering, a drag link, a double ended double acting pressure differentialoperatedmotor mounted on said frame member and extending parallel or substantially parallel thereto ,a two-part follow up valve for controlling the operation of said motor and mounted adjacent thereto, both parts of said valve being moved to effect said controlling operation, and force transmitting means interconnecting the power element of the motor, the pitman arm,'the two parts of the control valve and the drag link, said force transmitting means consisting of a plurality of juxtaposed relatively movable elements extending parallel or substantially parallel to said frame member and further consisting of a lever member connected to both of said valve parts, said member functioning as a lever of the third class when the valve is opened and functioning as a lever of the first class when the follow-up to lap operation of the valve is effected.

3. In a power steering mechanism for the dirigible wheels of a motor vehicle comprising a frame member extending parallel or substantially parallel to the ground, a pitmanarm mounted on said frame member and adapted to be manually oscillated in opposite directions for steering, a drag link, a double ended double acting pressure differential operated motor mounted on said frame member and extending parallel or substantially parallel thereto, a two-part follow up valve including a parallelopipedon body member and a spool shaped member reciprocably mounted therein for controlling the operation of said motor and mounted adjacent thereto, both parts of said valve being moved to effect said controlling'operation, and force transmitting means, including means interconnecting the parallelopipedon and power element of the motor and means interconnecting the pitman arm and spool shaped member, interconnecting the power element of the motor, the pitman arm, the two parts of the control valve and the drag link, said force transmitting means consisting of a plurality of juxtaposed relatively movable elements extending parallel or substantially parallel to said frame member.

4. In an automotive vehicle having a frame, a power steering mechanism for operating the dirigible wheels of the vehicle, said mechanism including a manually operable pitman arm, two spaced idler levers mounted on the frame of the vehicle, a drag link connected to said dirigiole wheels and means for actuating said drag link to efifect the steering operation, said means comprising a double acting double ended pressure differential operated motor including a power element, a follow up valve mounted exterior to said motor for controlling the operation thereof and force transmitting means interconnecting the drag link, pitman arm. idler levers, follow up valve and power element of the motor, said force transmitting means including a plurality of juxtaposed relatively movable elements extending parallel or substantially parallel to the frame of the vehicle. two of said elements being positioned side by side, two of said elements being telescoped one within the other and lying outside said motor and two of said elements being telescoped one within the other and having parts thereof lyin within said motor.

5. In an automotive vehicle provided with a steering wheel and a drag link, a power steering mechanism for moving said drag link to steer the vehicle. said power steering mechanism comprising a manually operable pitman arm, a double acting pressure differential motor having housed therein a power element and a diaphragm, said diaphragm comprising part of means for effect ing a resistance to the rotation of the steering wheel during the operation of the power steering mechanism, a two-part follow up valve for controlling the operation of said motor one of the valve parts constituting a spool shaped member and the other of said members constituting a parallclopipedon having an opening therein to receive said spool shaped valve member and force transmitting means interconnecting the diaphragm. the power element of the motor, the pitman arm, the drag link, the steering wheel and the two valve parts, said force transmitting means comprising a valve operating lever, means secured to one of the valve parts and constituting a part of the mounting for said lever and means interconnecting the said lever with the diaphragm and power element, said latter means comprising a pair of elements one telescoped within the other.

6. In an automotive vehicle rovided with a steering wheel and a drag link, a power steering mechanism for moving said drag link to steer the vehicle. said power steering mechanism comprising a manually operable pitman arm. a double acting pressure differential motor having housed therein a power element and a diaphragm.

sa d diaphragm comprising part of means for:

elfecting a resistance to the rotation of the steering Wheel during the operation of the power steering mechanism, a two-part follow up valve for controlling the operation of said motor, one of the valve parts constituting a spool shaped member and the other of said members constitutin a parallelopipedon having an opening there n to receive said spool shaped valve member and force transmitting means interconnecting the diaphragm, the power element of the motor. the pitman arm. the drag link. the steering wheel and the two valve parts, said force transmitting means comprising a valve operating lever member. means interconnecting one end of said member with the spool shaped member. means interconnecting the parallelopipedon with the lever member and means interconnecting the diaphragm with the lever member.

7. In a power steering mechanism for the dingible wheels of an automotive vehicle comprising a frame member extending parallel or substantially parallel to the ground, a steering wheel, a

pltman arm mounted on said frame member and adapted to be manually oscillated in opposite directions for steering, a drag link, a double-ended doubleactlng pressure differential operated motor mounted on said frame member and having housed therein a power element and a diaphragm, said diaphragm comprising part of means for efiecting a resistance to the rotation of the steering wheel during the operation of the power steering mechanism, a two part follow-up valve for controlling the operation of said motor and mounted adjacent thereto, both parts of said valve being moved' to effect said controlling operation, and force transmitting means interconnecting the power element of the motor, the diaphragm, the pitman arm, the two parts of the control valve and the drag link said force transmitting means comprising a lever member and further comprising a plurality of juxtaposed relatively movable elements extending parallel or substantally parallel to said frame member.

8. In a power steering mechanism for the dirigible Wheels of a motor vehicle comprising a frame member extending parallel or substantially parallel to the ground, a pitman arm adapted to be manually oscillated in opposite directions for steering. a drag link, a double acting pressure differential operated motor, a two-part fol low up valve for controlling the operation of said motor and mounted adjacent thereto, both parts of said valve being movable to effect said controlling operation, and force transm tting means interconnecting the power element of the motor. the p tman arm. the two parts of the control valve and the drag link. said force transmitting means consisting of a plurality of juxtaposed relatively movable elements and further consistin of a lever member connected to both of said valve parts. said member fulcruming at one point when the valve is opened and fulcruming at another point when the valve is lapped.

HENRY BAADE. 

